López-Corredoira, M.
Bibliographical reference
Astronomy and Astrophysics, Volume 469, Issue 2, July II 2007, pp.471-481
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7
2007
Journal
Citations
4
Refereed citations
4
Description
Aims:The non-conservative gravitational potential of barred galaxies, or
of any other non-axisymmetric structure, produces a loss of energy in
infalling particles of the intergalactic medium into the galaxy, which
are trapped in its potential. This dynamical friction can contribute
towards increasing the total mass of barred galaxies. Methods:
Analytical calculations of the energy loss are carried out using the
orbits of the particles derived numerically. Theoretical predictions are
compared with observations through the statistical analysis of the
rotation curves of barred and non-barred galaxies, either in cluster or
field galaxies. Results: There is a net effect of accretion, but
it is normally very low in relative terms. It is only significant
(>10% of the total mass of the dark matter halo in the life of the
galaxy) if the density of the intergalactic medium is higher than
~3× 1013~M_&sun; /Mpc3 (or considerably
lower in cases of motions of the galaxies close to the IGM average
motion, or perpendicular to the plane of the galaxy, or when the halo
mass is low). Data on rotation curves do not show clear trends towards
higher halo mass for barred galaxies, only slight trends for early-type
spiral galaxies. In any case, the statistical uncertainties are limited
to the detection of differences in masses >≈20%, so the effect of
bar-driven injection of intergalactic matter into galactic halos might
be present with relative contributions to the average mass of these
barred galaxies lower than 20%.